SampleRAE ASP-2000 AUTOMATIC SAMPLING PUMP Operation & Maintenance Manual Document Number: 010-4011-000 April 2003, Revision C1 ATTENTION! For European Applications The SampleRAE Automatic Sampling Pump (ASP-2000) is intrinsically safe for use in the following areas: A. 0575 II 1G DEMKO 03 ATEX 0204759X Eex ia IIC T4 B. Recharge batteries only in non-hazardous locations. C. Do not connect external cable to serial interface jack in hazardous locations. D. Use RAE Systems Adapter P/N 500-0072 for connection to communication port and charging jack only in a nonhazardous area. -READ BEFORE OPERATINGThis manual must be carefully read by all individuals who have or will have the responsibility for using, maintaining, or servicing this product. The product will perform as designed only if it is used, maintained, and serviced in accordance with the manufacturer's instructions. CAUTION! To reduce the risk of electric shock, turn off power before removing the monitor cover. Disconnect the battery before removing sensor module for service. Never operate the monitor while the cover is removed. Remove monitor cover and sensor module only in an area known to be non-hazardous. The battery of the SampleRAE unit will discharge slowly even if it is turned off. If the unit has not been charged for 7-10 days, the battery voltage will be low. Therefore, it is a good practice to always charge the unit before using it. It is also recommended to fully charge the unit FOR AT LEAST 10 HOURS before first use. See section 5 for more information on battery charging and replacement. The instrument should be calibrated with a standard flow meter before each day’s use. WARNING! For safety reasons this equipment must be operated and serviced by qualified personnel only. Read and understand instruction manual completely before operating or servicing. Batteries: Use only RAE Systems battery packs, part nos. 012-3050 or 012-3052. This instrument has not been tested in an explosive gas/air atmosphere having an oxygen concentration greater than 21%. Substitution of components may impair intrinsic safety. Recharge batteries only in nonhazardous locations. Static Hazard: Clean only with damp cloth. AVERTISSEMENT! Pour des raisons de sécurité, cet équipement doit être utilise, entretenu et répare uniquement par un personnel qualifie. Etudier le manuel d’instructions en entier avant d’utiliser, d’entretenir ou de réparer l’équipement. Des Batteries: Utiliser seulement L'ensemble de batterie RAE Systems, la référence 012-3050 au 012-3052. Cet instrument n’a pas été essaye dans une atmosphère de gaz/air explosive ayant une concentration d’oxygène plu élevée que 21%. La substitution de composants peut compromettre la sécurité intrinsèque. Ne charger Les batteries que dans emplacements désignés non dangereux. Danger risque d’origine électrostatique : Nettoyer uniquement avec un chiffon humide. Table of Contents 1. GENERAL INFORMATION ........................... 1-1 1.1 General Specifications ............................... 1-2 2. OPERATION OF SAMPLERAE .................... 2-1 2.1 Physical Description .................................. 2-2 2.2 Keys and Display ....................................... 2-3 2.3 Power On/Off ............................................. 2-4 2.4 Operation ................................................... 2-5 2.4.1 Sampling Operation............................. 2-6 2.4.2 Programming Operation ...................... 2-8 2.5 Alarm Signals........................................... 2-12 2.6 Back Light ................................................ 2-13 2.7 Remote Sampling Operation.................... 2-14 2.8 Battery Charging Operation ..................... 2-15 2.9 Sample Bag Collection............................. 2-17 3. THEORY OF OPERATION............................ 3-1 4. MAINTENANCE............................................. 4-1 4.1 Battery Replacement ................................ 4-1 4.2 Pump Replacement ................................... 4-5 4.3 Inlet Filter Replacement ............................. 4-7 5. TROUBLESHOOTING................................... 5-1 5.1 Special Diagnostic Mode ........................... 5-2 5.2 Troubleshooting Table ............................... 5-7 GENERAL INFORMATION 1. GENERAL INFORMATION SampleRAE is a hand held, battery powered, programmable Automatic Sampling Pump. It is designed to accept industry standard gas detection tubes or sorbent tubes. The user can program the sampling volume. A built-in flow sensor measures the exact amount of sample volume and then shuts off the pump automatically. • Lightweight and Compact 16 oz (454 g), Telephone handset size • Dependable and Accurate More than 16 hours of running time with the microcontroller, using alkaline or rechargeable batteries • User Friendly Menu driven, intuitive end-use operation SampleRAE (ASP-2000) kit includes: • Automatic sampling pump unit • Battery charger (for rechargeable versions) • Spare tube adapter • Alkaline battery adapter • Dust filter • Calibration accessories 1-1 GENERAL INFORMATION 1.1 General Specifications Table 1.1 Automatic Sampling Pump Specifications Size 7.5"L x 2.75"W x 1.5"H Weight 16 oz with battery pack Battery 4 AA size alkaline batteries or rechargeable Ni-Cad battery pack (snap in, field replaceable) Operating Hours 20 hours continuous sampling with alkaline battery or 16 hours with rechargeable battery Battery Charging 10 hours through built-in charger or an external battery charger Display 1 line by 8-character dot matrix LCD (0.4” character height) Inlet tube Adapter accepts industry standard 5 to10 mm gas detection or gas sorbent tubes Outlet Adapter 5/32” barb connection to collect air sample into Tedlar sampling bags Direct Readout accumulated sample volume, remaining run time, battery voltage and operating mode Intrinsic Safety UL & cUL Class 1, Division I, Groups A,B,C,D, Non-hazardous locations only (US & Canada) 0575 II 1G DEMKO 03 ATEX 0204759X Eex ia IIC T4 (Europe) (Continued) 1-2 GENERAL INFORMATION Operating Mode detection tube or sorbent tube mode Flow Rate flow calibration using external flow Calibration meter Sampling Volume user programmable from 50 to 1,000 cc in 50 cc increments for detection tube or 0.1 to 500 liter in 0.1 liter increments for sorbent tube Audible Alarm 90 dB buzzer @ 10 cm Visual Alarm flashing red LED EM Interference no effect when exposed to 0.43 mW/cm2 RF interference ( 5 watt transmitter at 12 inches ) Temperature 0o to 45oC (32o to 113oF) Humidity 0% to 95% relative humidity (noncondensing) Housing metal plated plastic, splash and dust proof, will withstand 3’ drop test Attachment Wrist strap 1-3 OPERATION OF SAMPLERAE 2. OPERATION OF SAMPLERAE The SampleRAE Unit is a hand-held automatic sampling pump. It allows a single hand operation to collect gas samples into gas detection tubes or sorbent tubes. Prior to factory shipment the SampleRAE is pre-calibrated with an external flow meter. However, the user should calibrate the instrument with a standard flow meter before the first use. After the unit is fully charged and calibrated, it is ready for immediate operation. Gas detection or sorbent tubes Light sensor LED light Liquid crystal display Key pads Charging LED Wrist strap Exit port Charging connector Figure 2-1 SampleRAE Unit 2-1 OPERATION OF SAMPLERAE 2.1 Physical Description The main components of the SampleRAE automatic sampling pump include: • Three keys for user to interact with the unit: 1 operation key 2 programming keys for normal operation or programming of the unit • Liquid crystal display with back light for direct readout and calculated measurements • Buzzer and red LED for alarm signal whenever the pump operation is completed • Wrist strap • Ambient light sensor • Charge contact for plugging directly to the charging station • Charging status indicator LED • Gas entry and exit ports 2-2 OPERATION OF SAMPLERAE 2.2 Keys and Display Light sensor Alarm LED’s Charge LED 50.0 cc Figure 2-2 Keypad and Display on Front Panel Key Function in Normal Operation [MODE] Turn on/off the power* and step through menu items [N/-] Negative acknowledgement or decrement value [Y/+] Start measurement, positive acknowledgement or increment value * Pressing and holding [MODE] for 5 seconds turns off the power to the unit. Unit will beep once per second and display a count-down timer during power-down sequence. Press [MODE] momentarily to step through menu items. To save time, press any key during message scrolling to skip to the end of the message. The SampleRAE includes a one line, eight digits, alpha/numeric, 5x7 dot matrix LCD display. The LCD displays the operation and programming menu and error messages. 2-3 OPERATION OF SAMPLERAE 2.3 Power On/Off Turn on the SampleRAE automatic sampling pump by pressing [MODE] for one second and then releasing it. The audio buzzer will beep once and the display will show “ON!..” and then “Ver n.nn” to indicate the unit’s current firmware version number. The model number and battery voltage are displayed. Then the display shows the currently selected operation mode: detection tube or sorbent tube, followed by the programmed sample volume. The display then shows “Start?” to indicate that the unit is ready to start sampling operation. Turn off the SampleRAE automatic sampling pump by pressing and holding [MODE] for 5 seconds. The unit will beep once per second during the power-down sequence with a count down timer showing the number of remaining seconds. The message “Off!...” flashes on the LCD display and the display will go blank indicating that the unit is turned off. 2-4 OPERATION OF SAMPLERAE 2.4 Operation The SampleRAE offers following two operation modes: Detection Tube Mode In this mode, the SampleRAE turns on the pump and pulls in a fixed volume of gas sample into a gas detection tube. Users can program the volume from 50 cc to 1000 cc in 50 cc increments. While the pump is running, the accumulated sample volume is displayed. When the programmed volume is reached, the pump will stop automatically. The user can NOT access other menus while the pump is running. Pressing any key while the pump is running will abort the sampling operation. Sorbent Tube Mode In this mode, the SampleRAE turns on the pump and pulls in a fixed volume of gas sample into a sorbent tube. The volume can be programmed from 0.1 liter to 500 liter in 0.1 liter increments. While the pump is running, the accumulated sample volume and the estimated remaining run time are displayed. When the programmed volume is reached, the pump will stop automatically. While the pump is running, the user CAN access other programming menu by pressing [MODE]. The user can also stop the pump by pressing [Y/+] when the display shows a “Stop?” message. After the SampleRAE is turned on and cycles through the start up displays, the current operation mode and programmed volume will be displayed followed by a “Start?” message. At this point, the user has two options: 1) start sampling operation, or 2) step through the programming menu. 2-5 OPERATION OF SAMPLERAE 2.4.1 Sampling Operation The sampling operation involves the following sampling phases: • Ready • Tube Preparation • Insert tube • Start sampling • Display volume and time • Remove tube Ready Unit is ready to start sampling. The display shows a “Start?” message. Tube Preparation Break both ends of a new detection or sorbent tube using the tip cutter on the tube cap of the SampleRAE. The tube contents may be hygroscopic and should be used within a short time of opening of the tube. CAUTION: Wear hand and eye protection when breaking tube tips. Use caution in handling tubes with broken ends. Keep away from children. Detection or sorbent tubes should be disposed of according to local regulations. Tube insertion Insert the tube securely into the tube inlet of the SampleRAE with the tube arrow pointing towards the unit. Start Sampling Press [Y/+] to start the sampling pump. 2-6 OPERATION OF SAMPLERAE Display Volume and Time While the pump is running, the accumulated volume will be displayed in units of cc or liter. The estimated remaining run time will also be displayed in the sorbent tube mode. When the programmed volume is reached, the pump will stop and a message “Done!” and “Remove Tube!” will be displayed for 2 seconds. The LED will flash once and the buzzer will sound for 1 second to indicate the completion of the sampling operation. Tube Removal Remove the tube from the tube inlet. Dispose the tube according to local regulations. Abort Sampling During waiting period of detection tube operation, any key pressed will abort the sampling operation. While the display shows “Stop?” menu in sorbent tube mode, press the [Y/+] key will also abort the sampling operation. The accumulated volume will be displayed in this case. 2-7 OPERATION OF SAMPLERAE 2.4.2 Programming Operation While the display shows “Start?” menu, press [MODE] to step through the programming menus, which are arranged in a “round robin” order. To choose a specific display, press [MODE] one or more times until the desired display appears. Start? Bat=4.8 V Change Volume? Change Tube Type? Calibrate Flow? 1) Start? The pump is ready for sampling operation. Press [MODE] to advance to the next menu. If a tube is inserted at this point, [Y/+] can be pressed to start a sampling. (See section 2.4.1). 2) Change Volume? This menu allows users to change the programmed sample volume. Press [Y/+], the currently programmed volume will be displayed. Press [Y/+] to increment the volume and [N/-] to decrement the volume. Press [MODE] to exit the volume change menu. If the volume is changed from a previously saved value, a “Save?” message will appear. Press [Y/+] to confirm the change. Press [N/-] or [MODE] to discard the change and advance to the next menu. If user does not want to change the volume, press [MODE] or [N/-] to skip to the next menu. 2-8 OPERATION OF SAMPLERAE 3) Calibrate Flow? This menu allows users to calibrate the flow sensor inside the SampleRAE. An external flow meter, an accurate gas flow calibrator or a mass flow meter*, is required to perform the following calibration procedure. Press [Y/+] to proceed. *If an external flow meter is not available, user can use the calibration tube as a simple (but less accurate) flow standard. A typical calibration tube will provide a flow rate between 120 to 140 cc per minute. The flow rate of each tube is measured in the factory and recorded on the plastic bag. However, this flow rate changes as the pump ages, and therefore an external flow meter is ultimately necessary. Zero calibration The display shows a message “Zero….” for 4 seconds followed by a “Continue” message. The flow sensor zero point is calibrated automatically and the unit displays the next submenu. Span calibration The pump is turned on and the display shows a flow reading “XXX ccm” where XXX is the flow rate in cc per minute based on previous calibration. Insert the calibration tube into the tube inlet of the SampleRAE. Note: make sure that the arrow on the calibration tube is pointing toward the inlet of the SampleRAE. Connect an external flow meter to the open end of the calibration tube. Measure the actual flow rate from the external flow meter. Press [Y/+] to increment the flow value and [N/-] to decrement the flow value so that it matches the actual flow rate reading of the external flow meter. Press [MODE] to exit the flow rate change menu. A “Save?” message will appear. Press [Y/+] to confirm the change 2-9 OPERATION OF SAMPLERAE and save the new calibration value. Press [N/-] or [MODE] to abort and exit the calibration submenu. Note: In order to achieve the best flow accuracy, it is recommended that the actual detection or sorbent tube be used during the calibration procedure together with an external flow meter. 4) Change Tube Type? This menu allows users to change the operation mode of SampleRAE. Press [Y/+], the current mode (Detection or Sorbent) is displayed. Press [N/-] to toggle to the other mode. Press [Y/+] to accept the current mode. Press [MODE] to exit the mode change menu. If the operation mode is changed from a previously saved one, a “Save?” message will appear. Press [Y/+] to confirm the change. Press [N/-] or [MODE] to discard the change and advance to the next menu. 5) Bat=4.8V This menu displays the current battery voltage of SampleRAE. Press any key to continue to the next menu. Note: a fully charged battery pack should show 4.8 volts or higher. When the battery voltage falls below 4.4 volts, a flashing “Bat” will appear as a warning message. There is about 20-30 minutes of run time left before the SampleRAE will be turned off automatically when the battery voltage falls below 4.2 volts. 6) Stop? In sorbent tube operation mode, if the pump is already running, the “Start?’ menu will be changed to a “Stop?” menu. Press [MODE] to advance to the next menu. Press [Y/+] to stop the pump and abort the sampling operation. The accumulated sample volume up to this point will be displayed. 2-10 OPERATION OF SAMPLERAE Correction Factors In Detection Tube Mode, it is sometimes necessary to multiply the final readings by a correction factor (CF) specific for the type of tube. This occurs because the tubes are calibrated with a hand pump that has a different flow pattern than the SampleRAE. A list of correction factors is given in Technical Note 154 at www.raesystems.com. In most cases, the corrections are minor and lead to a <10% to 15% overestimation and therefore err on the safe side, and the correction might be omitted. However, for some tubes, the corrections are more significant and must be used. For best accuracy the user should test their sample gas and tube batch with both the Hand Pump and SampleRAE to obtain a more accurate correction factor to apply to subsequent SampleRAE tube readings. 2-11 OPERATION OF SAMPLERAE 2.5 Alarm Signals At the end of each sampling period, the buzzer and red flashing LED are activated once to indicate the completion of the sampling operation. If the operation is aborted, the buzzer and red flashing LED will be activated twice. In addition, the SampleRAE will alarm if the battery voltage falls below a pre-set voltage level (4.4 V). When the low battery alarm occurs, the red LED will flash once a second and the buzzer will beep once a minute. There will be approximately 20-30 minutes of operating time left. When the battery voltage falls below 4.2 V, the unit will be turned off automatically. Alarm Conditions and Signals Condition Alarm Signal Complete Operation 1 beeps/flash plus “Done!” message in LCD Abort Operation 2 beeps/flash plus “Abort!” message in LCD Low battery 1 flash per second, 1 beep per minute plus “Bat” message in LCD 2-12 OPERATION OF SAMPLERAE 2.6 Back Light The LCD display is equipped with an LED back light to assist in reading the display under poor lighting conditions. The ambient light is sensed continuously and the back light will be turned on automatically if the ambient light is below a threshold level. The back light will be turned off automatically when the ambient light exceeds the threshold level. See section 5.1 for instructions on how to set the threshold level of the back light. Note: The LED back light consumes a higher amount of energy from the battery and shortens the operating time of the unit by 20 - 30%. 2-13 OPERATION OF SAMPLERAE 2.7 Remote Sampling Operation The SampleRAE includes an integrated diaphragm pump that provides a minimum flow rate of 250 cc per minute (with no tube in place). Connecting a 1/4 inch Tygon tubing with 1/8 inch inside diameter to the gas inlet port of the SampleRAE, this pump can pull in air sample from 200 feet away horizontally, or 90 feet vertically. Note: When the SampleRAE is pulling gas sample from a remote location, it is necessary to account for the volume inside the long tubing so that the total sample volume is calculated correctly. See Technical Note 140 for details on tubing volumes and delay times. Remote sampling hoses of 15 feet (P/N 010-3009015) and 35 feet (P/N 010-3009-035) are available with direct connection to the SampleRAE and with a tube holder at the end of the hose. 2-14 OPERATION OF SAMPLERAE 2.8 Battery Charging Operation The SampleRAE operates conveniently with alkaline batteries, but offers a rechargeable Ni-Cad battery pack as an option. The charging circuit is built into the SampleRAE unit. It only needs a regular AC to 12 V DC adapter (wall mount transformer) to charge the rechargeable battery pack inside the unit. 1. Connect the AC adapter (or the optional automotive charging adapter) to the DC jack on the SampleRAE unit. If the unit was off, it will automatically turn on. 2. The first message displayed will be “Deep discharge?” This message will remain on the display for three seconds. If the user wants to discharge the battery pack, affirm this query with [Y/+], otherwise the unit will skip this function and move on to the charge mode after 3 seconds. Note: deep discharge recovers the Ni-Cad battery from a memory effect and it is needed only when the battery run time is below normal. Deep discharge may take up to 10 hours depending on the charge level in the battery. 3. While charging, the display message will alternate between “Charging” and “Bat=x.xV” (x.x is the present battery voltage). The LED should be red in color when charging. 4. When the battery is fully charged, the LED will change from red to green and the message “Fully charged” will appear on the display. The red color indicates that the battery is being charged. The green color indicates that the battery is fully charged. After the battery is fully charged, the unit will enter the “trickle charge” mode. In this mode, the red LED will turn on 2-15 OPERATION OF SAMPLERAE for two or three seconds, every minute, to maintain the full charge and avoid overcharging. A completely discharged SampleRAE unit will be charged to full capacity within 10 hours. The battery will be drained slowly even if the unit is turned off. If the unit has not been charged for 7-10 days, the battery voltage will be low. The factory supplied Ni-Cad battery is designed to last for 16 hours of normal operation (no alarm, no back light condition), for a new battery under the best conditions. As the battery becomes older or is subject to adverse conditions, like cold ambient temperatures, the battery capacity will be reduced significantly. The unit can be run off a wall mount adapter, as long as the rechargeable battery is in place. CAUTION: A unit plugged into a wall mount adapter is NOT considered intrinsically safe. 2-16 OPERATION OF SAMPLERAE 2.9 Sample Bag Collection The SampleRAE can be used to collect a fixed amount of gas into a sample collection bag for analysis or other applications. An outlet adapter is provided in the standard SampleRAE kit. Connect a sample collection bag to the outlet adapter through a short piece of Tygon* tubing. Screw the outlet adapter into the exit port on the side of the SampleRAE unit. Make sure that the O-ring of the outlet adapter is in place so that it can make an air tight seal between the outlet adapter and the exit port. * Because Tygon absorbs or reacts with many chemicals, Teflon or metal tubing is recommended for any sections longer than a few inches. Program the sample volume through the programming menu (see Section 2.4.2). Press [Y/+] to start the pump. When the desired volume of sample gas is collected in the bag, the pump will shut off automatically. 2-17 THEORY OF OPERATION 3. THEORY OF OPERATION The SampleRAE unit uses a miniature diaphragm pump to pull a fixed amount of gas sample into a detection tube or a sorbent tube. An electronic flow sensor inside the unit measures the actual gas flow and integrates the total sample volume every 0.5 second. The exhaust gas exits through a port on the side of the housing. LCD display keypad buzzer microprocessor flow sensor detection or sorbent tube pump LED battery light sensor charger Figure 3-1 SampleRAE Block Diagram During detection tube sampling operation, the flow pattern of the colorimetric tube is taken into consideration and the sample volume is adjusted to compensate for the flow pattern effect on the detection tube. (See Technical Note 154 for further corrections.) During sorbent tube operation, exact volume is calculated based on the flow rate without any compensation. A single chip microcomputer is used to control the operation of the alarm buzzer, LED, pump and light sensor. It measures the flow sensor readings and calculates the total sample volume based on calibration data. A two-point calibration is used to calibrate the sensor to a known flow rate and 3-1 THEORY OF OPERATION zero flow (i.e. no flow). The calibration data are stored in non-volatile memory. A liquid crystal display consisting of a single row of eight alpha/numeric characters is used to display the volume readings and menu messages. The user interacts with the unit through three keys on the front panel keypad. The unit is powered by a rechargeable Ni-Cad battery, or an alkaline battery pack. NOTE: The printed circuit board of the unit is connected to the battery pack even if the power is turned off. Therefore, it is very important to disconnect the battery pack before servicing or replacing any components inside the unit. Severe damage to the printed circuit board may occur if the battery pack is not disconnected before servicing the unit. WARNING! To reduce the risk of ignition of hazardous atmospheres, recharge battery only in an area known to be non- hazardous. Remove and replace battery only in an area known to be non- hazardous. Ne charger les batteries que dans emplacements désignes non dangereux. 3-2 MAINTENANCE 4. MAINTENANCE The major maintenance items of the SampleRAE are: • Battery Pack • Sampling Pump • Inlet connectors and filter 4-1 MAINTENANCE 4.1 Battery Replacement When the display shows a flashing message “Bat”, the battery requires replacement or recharging. The battery may be replaced in the field (in area known to be nonhazardous) if required. If a rechargeable battery pack is used, it is recommended to recharge the SampleRAE unit upon returning from fieldwork. A fully charged battery powers a SampleRAE unit for 16 hours continuous operation. The charging time is less than 10 hours for a fully discharged battery. The built-in charging circuit is controlled by two-step constant voltage / constant current charging to prevent over-charging. WARNING! To reduce the risk of ignition of hazardous atmospheres, recharge battery only in area known to be non- hazardous. Remove and replace battery only in area known to be non- hazardous. 4-2 MAINTENANCE Battery Cover Battery Pack Battery Compartment Charger Connector Wrist strap Figure 4-1 Replacing the Battery 1. Turn off power to the SampleRAE. 2. Unscrew the two battery compartment screws, located on the bottom of the unit, and remove the cover. 3. Remove the battery from the battery compartment. 4. Connect the rechargeable battery pack to an external charging station (optional) for charging if necessary. 5. Replace a fully charged spare battery pack inside the battery compartment. Make sure the battery pack is oriented properly inside the compartment by aligning the pins on the unit with the contacts on the battery pack. 6. Close the battery compartment cover and tighten the two screws. 4-3 MAINTENANCE Replacing Alkaline Battery Adapter An alkaline battery adapter is supplied with each SampleRAE kit. It accepts four AA size alkaline batteries and can be used in place of the rechargeable battery pack to provide approximately 20 hours of operation. 1. Insert four fresh AA size alkaline batteries into the alkaline battery adapter. Make sure that the polarity of the batteries is correct. 2. Follow the same procedure as described above to replace the battery adapter. The internal charging circuit is designed to prevent charging to alkaline batteries when alkaline batteries are installed. Plugging a wall mount adapter into the unit with alkaline batteries will not charge the batteries. Note: The AA Alkaline battery adapter supplied by RAE Systems Inc. is intrinsically safe! 4-4 MAINTENANCE 4.2 Pump Replacement The sampling pump is a positive displacement diaphragm pump. When approaching the end of the specified life time of the pump, it will consume higher amount of energy and reduce its sample draw capability significantly. When this occurs, it is necessary to replace or rebuild the pump. To check the pump flow, connect the inlet port to an external flow meter (such as the mass flow meter, gas flow calibrator or a floating ball flow meter). The flow should be greater than 250 cc/min. Battery Cover Bottom Cover Pump Top Cover Figure 4-2 Replacing the Pump 4-5 MAINTENANCE Pump Replacement 1. Turn off SampleRAE power. 2. Open the battery cover, remove the battery pack, unscrew the six screws to open the bottom cover. 3. Unplug the pump from the PCB. Unscrew the two screws that hold the pump assembly to the PCB. Disconnect the Tygon tubing that connects the pump to the gas inlet port and exit port. 4. Replace a new pump assembly. Connect the Tygon tubing to the gas inlet port. Plug the pump connector back into the PCB and screw down the pump assembly to the board. 5. Replace the bottom cover and tighten the six screws. Replace the battery pack and its cover. 4-6 MAINTENANCE 4.3 Inlet Filter Replacement The SampleRAE inlet consists of a rubber tube adapter and a porous metal dust filter. The standard rubber tube adapter will accept 5 to 8 mm gas detection or sorbent tubes. If a 10 mm tube is used, a special rubber tube adapter is needed. The rubber tube adapter needs to be replaced when it becomes worn from repeated inserting and removing tubes. Figure 4-3 shows the drawing of the inlet assembly. Figure 4-3 Inlet Filter Assembly The porous metal filter prevents dust or glass debris from entering into the sampling pump. It needs to be replaced periodically so that it will not be clogged by the dust and glass debris. To replace the metal filter, first remove the pump adapter nut by unscrewing the nut counter clockwise. Pull out the tube adapter from the unit. Use a screw driver to pop out the metal filter by pushing from the open end of the tube adapter. Insert a new filter into the rubber adapter. Place the tube adapter with the filter back into the unit and screw down the pump adapter nut. 4-7 TROUBLESHOOTING 5. TROUBLESHOOTING To aid the user in diagnosing the unit, the unit has a special diagnostic mode that can display critical, low level parameters. Section 5.1 describes the operation of the diagnostic mode. Section 5.2 summarizes the frequently encountered problems and suggested solutions. Turning on the SampleRAE unit in diagnostic mode and using the troubleshooting table in Section 5.2, the user can usually narrow the problem down to one or two areas and correct the problem without having to return the unit for repair. WARNING! The diagnostic mode allows the user to set several low level parameters that are very critical to the operation of the unit. Extra care should be taken when setting these low level parameters. If the user is not familiar with these parameters and sets them incorrectly, it may cause the unit to shut down or malfunction. Use by qualified personnel only. 5-1 TROUBLESHOOTING 5.1 Special Diagnostic Mode To place the unit into the special diagnostic mode, first turn the unit off. Next push and hold [Y/+], while still holding [Y/+], also push and hold [MODE] for at least two seconds. After the required delay, release both keys, the unit will now go through the normal start-up display sequence and display a “Diagnostic mode” message. At the end of the special mode start-up, the display will show the message “VAC xxxx”. This is the first diagnostic menu. Other diagnostic menus of the unit are available as shown below. They can be reached by pressing [MODE] repeatedly until the desired parameters are displayed. Table 5-1 Diagnostic Mode Menu Key Action Display Raw reading [MODE] Off reading [MODE] Flow reading [MODE] Adjust Pump? [MODE] Calibrate Flow? [MODE] LCD contrast [MODE] Pump current [MODE] Alarm On/Off? [MODE] Ambient light [MODE] Back light threshold [MODE] PC Communication? 5-2 TROUBLESHOOTING The following is a brief description of the diagnostic functions: 1) Raw reading The raw sensor readings are displayed as “VAC xxxx” where xxxx is a 4 digit number. This raw sensor reading provides a quick diagnosis on the response and the sensitivity of the flow sensor while the pump is running. The sensor should read above 3000 when there is no blockage to the inlet port. Block the inlet port with a finger, the sensor reading should drop to 1800 or less. If the raw reading is not changing or falls outside this range, the flow sensor or the associated electronics may be defective. 2) Off reading The pump is turned off and the raw sensor reading is displayed. This reading provides a quick diagnosis on the base line signal of the flow sensor while the pump is turned off. The sensor reading should be between 1200 to 1800. If the raw reading is outside of this range, the flow sensor or the associated electronics may be defective. 3) Flow Reading This menu provides a quick diagnosis on the calibration of the flow sensor. The pump is turned on and the calibrated flow reading is displayed as “xxx ccm” where the flow rate is expressed in cubic centimeter per minute. Connect an external flow meter to the inlet port. Compare the flow meter reading with the displayed reading. If the flow reading is more than 10% off the external flow meter reading, it is necessary to perform a new flow calibration to maintain the flow measurement accuracy. 5-3 TROUBLESHOOTING 4) Adjust Pump? This menu allows the user to adjust the pump drive to increase or decrease the power delivered to the pump. Note: In most cases pump drive adjust is not required, in which case the user should press [MODE] to exit this display. If the user want to adjust the pump, press [Y/+]. The current pump drive is displayed. The nominal value of the pump drive is set to 250. The maximum drive is 255 and it is the maximum power to be delivered to the pump. [Y/+] can be used to increase or [N/-] to decrease the pump drive. When pump drive exceeds 255, it returns to 0. If the pump drive value has been changed, a message “Save?” will appear. Press [Y/+] to confirm the change, [N/-] or [MODE] to discard the changes. 5) Calibrate Flow? This menu allows user to calibrate the flow sensor of the SampleRAE unit using an external flow meter. The calibration procedure is identical to that of Section 2.4.2. However, in diagnostic mode, there is no error checking of the flow sensor readings during calibration. Therefore, any sensor reading is considered valid. If the user accidentally entered a wrong value or performed an illegal operation during regular calibration, this function can be used to recover from the error. 6) LCD Contrast This display allows the user to adjust the LCD contrast. Press [Y/+] to increase the contrast and [N/-] to decrease the contrast. The bar graph shows the current LCD contrast setting. If the display appears blank or very faint, press the [Y/+] several times to increase the contrast. 5-4 TROUBLESHOOTING 7) Pump Current This display can be used to diagnose the operation of the pump. The pump current is displayed as “Pump=xxx”. When the pump is operated normally, the pump reading should be between 4 to 12. When the inlet is blocked, the pump reading should increase by 4 to 6. If the pump reading is zero or does not change when the inlet is blocked, the pump may be defective or there is a leak in the inlet. 8) Alarm On/Off? This display can be used to test the operation of the alarm buzzer and red LED. The display shows “Alarm” then “On?…”. Press [Y/+], the buzzer will beep and the red LED will light up. The display shows “Off?..” Press [Y/+] again to turn off the buzzer and LED. Press [MODE] to move to the next menu. 9) Ambient Light This display can be used to diagnose the operation of the ambient light sensor. The present light sensor reading is displayed as “Lite=xxx”. In a brightly lit room, the light sensor reading should be above 130. The user can shade the light sensor (which is located at the upper left corner of the display membrane) with their hand and watch the light sensor reading. The light sensor reading should drop to less than 100. If the light sensor reading is outside this range or does not change when the sensor is blocked, the light sensor or associated electronics may be defective. 5-5 TROUBLESHOOTING 10) Back Light Threshold This display can be used to adjust the LCD back light turn on and off threshold level. The display shows the current threshold level as “Trip=xxx”. First determine the appropriate light level to turn on the back light from the previous menu. Use [Y/+] or [N/-] to increase or decrease the trip value until it is about the same as the previously determined threshold value. Press [MODE] to exit this display. If the threshold value is changed, a message “Save?” will appear. Press [Y/+] to confirm the change, [N/-] or [MODE] to abandon the changes. 11) PC Communication? This function allows the unit to communicate directly with a PC through the serial port. This function is reserved for advanced diagnostic capability by an authorized service center. 5-6 TROUBLESHOOTING 5.2 Troubleshooting Table Table 5-2 Problem Possible Reason Possible Solution Cannot turn on power after charging the battery Discharged battery. Defective battery. Microcomputer hang-up. Charge or replace battery. No LED or LCD back light Trigger level too low, defective LED or LCD back light. Adjust trigger level. “Bat” message in operation Discharged battery. Recharge battery. Buzzer Inoperative Bad buzzer. Call authorized service center. Cannot turn off unit or corrupted characters in LCD display Microprocessor hang-up. Disconnect and reconnect battery to reset computer. Calibration error message Defective flow sensor. Disconnect, then connect battery to reset computer. Call authorized service center. Call authorized service center. Incorrect flow set up. Excessive pump noise or no inlet air suction. Blocked inlet path. Inlet flow too low Pump diaphragm damaged or has debris. Flow path leaks or blocked. Defective pump. Ensure correct flow, replace sensor. Check inlet connection. Replace a new pump. 5-7 Check flow path for leaks; sensor module, Teflon tube connection TROUBLESHOOTING Replace pump 5-8 RAE Systems, Inc. Main Office 1339 Moffett Park Drive Sunnyvale, California 94089, USA Contact Numbers Fax 408.752.0724 Telephone 408.752.0723 Instrument Sales 877.RAE.CUSTOMER (877.723.2878) Tubes Sales 888.RAE.TUBE (888.723.8823) Technical Support 888.723.4800 E-mail RaeSales@raesystems.com Tech@raesystems.com Website www.raesystems.com NOTE: Before returning the unit for service or repair, please obtain a Return Material Authorization (RMA) Number for proper tracking of your equipment. Packages without RMA Numbers will be refused at the factory.